[Thadlerian]

It depends on who's going to start reading her.

My first Le Guin was Orsinian Tales, an underdog Alternative History short story collection. It is blindingly beautiful, and should be a sure start-up for anyone not really into SF/F. For an impression of her human feeling, see if you can dig this one up.

For a SF fan, The Left Hand of Darkness is a great introduction.

For a Fantasy fan, A Wizard of Earthsea. Alternatively, Gifts. But Gifts is so great, it feels like the quintessence of everything she's written to date, you should really save that one for later. Even though it as well would have been a good starting point, especially human feeling considered.